Imperial High Commander N'Vol was supreme commander of the Romulan armed forces in the mid-2370s. He's described as having thin, graying hair and chiseled features that were rapidly creasing due to the pressures he's endured in prosecuting the war with the Dominion.
N'Vol, Senator Tal'Aura and Tal Shiar General Valnor charged Centurion Shinzon and his regiment with destroying all evidence of an unsanctioned, top-secret Tal Shiar laboratory on the planet Goloroth, which lies in the Romulan Neutral Zone in direct violation of the Treaty of Algeron.
N'Vol nodded curtly in greeting Shinzon and then explained that Starfleet and the Klingon Defense Force, which would be storming Goloroth to take over a Dominion communications relay, must not find any trace of the Tal Shiar facility.
Finally, N'Vol stressed to Shinzon that this briefing never happened, and that he, Tal'Aura and Valnor were never there. In return for his silence and subsequent victory on Goloroth, Shinzon was promised the command of his own Warbird and the ability to choose his own crew. (TNG - Tales of the Dominion War short story: "Twilight's Wrath")